Ink for dyeing a plastic lens and method of dyeing a plastic lens using the ink

ABSTRACT

The purpose of the present invention is to provide an ink for dyeing a plastic lens, capable of favorably dyeing the plastic lens by a vapor transfer dyeing method, and a method of dyeing a plastic lens by using the ink. In the present invention, an ink for dyeing a plastic lens, the ink being applied by an ink jet printer, sublimated in vacuum and deposited on the plastic lens to dye the lens, wherein the ink includes at least one sublimatable disperse dye of an anthraquinone dye, a quinophthalone dye, and an azo dye of thiazole type.

TECHNICAL FIELD

The present invention relates to an ink for dyeing a plastic lens and amethod of dyeing a plastic lens using the ink.

BACKGROUND ART

As a method of dyeing a plastic lens, a method of immersing a lens in adyeing liquid (solution) for a predetermined time (dip dyeing method)has been known. However, this method involves problems such as poorworking circumstance and difficulty for the dyeing of a lens at highrefractive index. In view of the above, the present applicant hasalready proposed a dyeing method of applying (outputting) a sublimatabledye to paper (base body) by an ink jet printer and placing the same invacuum in noncontact with a lens as disclosed in Japanese Patentunexamined publication No. 2001-59950 (hereinafter referred to as avapor-deposition transfer dyeing method).

In this vapor-deposition transfer dyeing method, existent inks for inkjet printers or inks used for general textile dyeing involve problemsthat the heat resistance and sublimation property of dyes are poor anddyeing by the use of such inks causes uneven dyeing or poor colorationto the lens after dyeing.

The present invention has been made in view of the above circumstancesand has an object to provide an ink for dyeing a plastic lens capable ofappropriately dyeing a plastic lens by the vapor-deposition transferdyeing method, and a method of dyeing a plastic lens by using the ink.

DISCLOSURE OF THE INVENTION

For solving the foregoing object, the present invention has thefollowing constructions.

(1) An ink for dyeing a plastic lens, the ink being to be applied to abase body by an ink jet printer, and sublimated in vacuum and depositedon the plastic lens to dye the lens,

wherein the ink includes at least one sublimatable disperse dye of ananthraquinone dye, a quinophthalone dye, and an azo dye of thiazoletype.

(2) The ink for dyeing a plastic lens in (1), further including adispersant for dispersing the dye in an aqueous system.

(3) The ink for dyeing a plastic lens in (2), further including ahumectant used for keeping the ink moistened and a hydrophilic polymericmaterial for preventing sublimation of the humectant.

(4) The ink for dyeing a plastic lens in (1), wherein a compoundingratio of the dye is in a range of 2.0% by weight to 20.0% by weight.

(5) The ink for dyeing a plastic lens in (1), wherein a particlediameter of the dye is 1 μm or less.

(6) A plastic lens dyeing method of dyeing a plastic lens by sublimatinga plastic lens dyeing ink in vacuum and depositing the ink on the lens,including: a step of forming a print area by applying the ink to a basebody by an ink jet printer, the ink including at least one sublimatabledisperse dye of an anthraquinone dye, a quinophthalone dye, and an azodye of thiazole type; a step of placing the thus formed print area andthe lens to face each other in noncontact relation; and a step ofheating at least the print area to sublimate and deposit the dye on thelens.

(7) The plastic lens dyeing method in (6), further including a step ofheating the lens on which the dye has been deposited, at a predeterminedtemperature.

(8) The plastic lens dyeing method in (6), wherein the ink includes ahumectant used for keeping the ink moistened and a hydrophilic polymericmaterial for preventing sublimation of the humectant.

(9) The plastic lens dyeing method in (6), wherein the ink includes ahumectant used for keeping the ink moistened and a surface of the basebody to be applied with the ink is previously coated with a hydrophilicpolymeric material.

BRIEF EXPLANATION OF DRAWINGS

FIG. 1 is a schematic view showing the flow of a vapor depositiontransfer dyeing method; and

FIG. 2 is a schematic structural view of a dyeing jig.

BEST MODE FOR PRACTICING THE INVENTION

Now, an embodiment of the present invention is to be described withreference to the drawings. FIG. 1 is a schematic view showing the flowof a vapor deposition transfer dyeing method.

(1) Ink Preparation

At first, a dyeing ink used in an ink jet printer is prepared. In thisembodiment, dyes for three colors of YELLOW, RED and BLUE (material fordyeing) are used to prepare dyeing inks of three colors of YELLOW, REDand BLUE. Any dye having a sublimation property can be used andhydrophobic disperse dyes are used preferably. Further, in thisembodiment, since the dye is sublimated by heating the dye at apredetermined temperature, it is necessary to use a dye capable ofresisting the heat during sublimation.

Taking the foregoings into consideration, an anthraquinone disperse dyerepresented by the following formula (1) or quinophthalone disperse dyerepresented by the following formula (2) is used preferably as theYELLOW dye.

where R1, R2 each represents hydrogen, an alkyl group of 1 to 3 carbonatoms, an amino group or imino group. R3, R4 each represents hydrogen, ahalogen group, an alkyl group of 1 to 3 carbon atoms, a hydroxy group,an amino group or imino group. R5, R6 each represents hydrogen, an alkylgroup of 1 to 3 carbon atoms, sulfonate group, amino group, imino group,halogen group or ether group (having a structural formula —O—R, in whichR represents, for example, an alkyl group of 1 to 10 carbon atoms, aphenyl alkyl group of 1 to 10 carbon atoms or a phenyl group). R7represents hydrogen or a sulfonate group.

where R8, R9 each represents hydrogen, a hydroxyl group, a halogen groupor an alkyl group of 1 to 3 carbon atoms.

Specifically, color ID number (C. I. Disperse, hereinafter referred toas C.I. number) YELLOW 13, YELLOW 51, YELLOW 51, or YELLOW 64 can beused suitably.

Further, an anthraquinone disperse dye represented by the formula (1) oran azo disperse dye of thiazole type represented by the followingformula (3) is used preferably as the RED dye.

where R10, R11 each represents hydrogen, an alkyl group of 1 to 3 carbonatoms, an alkenyl group of 1 to 3 carbon atoms or an ether group (havinga structural formula: —O—R in which R represents, for example, an alkylgroup of 1 to 10 carbon atoms, a phenyl alkyl group of 1 to 10 carbonatoms, or a phenyl group). R12, R13 each represents an alkyl group of 1to 3 carbon atoms, alcohols of 1 to 3 carbon atoms, carboxylic acid of 1to 3 carbon atoms or esters thereof. R14 represents hydrogen, an alkylgroup of 1 to 3 carbon atoms or an imino group.

Specifically, C.I. Numbers RED 4, RED 11, RED 15, RED 55, RED 58, RED60, RED 86, RED 91, RED 92, RED 127, RED 152, RED 189, RED 229 or RED302 is used preferably.

Further, an anthraquinone disperse dye represented by the formula (1) oran azo disperse dye of thiazole type represented by the formula (3) isused preferably as the BLUE dye.

Specifically, C.I. Numbers BLUE 56, or BLUE 73 can be used suitably.

The average particle diameter of the dye is, preferably, from 0.05 μm to1 μm and the maximum particle diameter is 3 μm or less, furtherpreferably, 0.05 μm to 0.5 μm and the maximum particle diameter is 1 μmor less. If the particle diameter of the dye is greater than thatdescribed above, clogging may possibly be caused upon discharging theink from the ink jet printer.

The inks of three colors of YELLOW, RED and BLUE are individuallyprepared. The dyes for respective colors are put in separate vessels, adispersant and pure water (or ion exchanged water) are added to eachvessel and agitated sufficiently.

The ratio of the dye in the ink prescription or formulation is,preferably, from 0.1% by weight to 20.0% by weight, more preferably,1.0% by weight to 20.0% by weight and, further preferably, 2.0% byweight to 20.0% by weight. If the dye is less than 0.1% by weight, adesired color density can not be often obtained. Further, if the dyeexceeds 20.0% by weight, the dispersibility of the dye becomes poor.

Further, it is preferred that the dispersant used is not thermallydecomposed and has a heat resistance but those decomposed by heat mayalso be used so long as they give no undesired defect on the dyeing.

Each of the vessels in which the dye and the dispersant are sufficientlyagitated is placed in a container containing cooling water and treatedby a bead mill for a specified period of time to finely disperse theparticles of the dye. Then, each liquid (solution) is filtrated undersuction through a filter of a pore size of about 1 μm (glass fiberfilter paper GF/B) to remove particles of larger size and dusts.Subsequently, pure water or ion exchange water is added for regulationto attain a specified ink density, to complete ink preparation.

(2) Production of a Print Base Body

The inks of three colors prepared as described above are contained incommercially available ink cartridges 41 for the ink jet printer andthey are mounted to the ink jet printer 40. A commercially availableprinter may be used as the printer 40.

Then, for printing desired colors by the printer 40, hue and densitythereof are controlled by using a commercial personal computer(hereinafter referred to as PC) 50. Since the control for the hue isconducted by a drawing software of the PC 50, data on the desired huecan be stored in the PC 50 and printing can be conducted repeatedly withan identical hue as required. Further, since the density of the hue isalso digitally controlled, printing can be made repeatedly at the samedensity as required.

Commercial A4 size paper 1 is used as a base body on which the ink(sublimatable dye) is printed. The paper 1 is not limited to paper andthere is no restriction so long as it is printable by the printer 40.Since it is heated in the vapor deposition transfer dyeing, it ispreferable to use paper or the like having one or both black-coloredfaces for the purpose of enhancing the efficiency of heat absorption.

The paper 1 is set in the printer 40, and printing is conducted on thepaper 1 at a predetermined hue and density by operating the PC 50. Anink-applied print area (colored layer) 2 is printed in a circular formon the paper 1. It is preferable that the print area has a diametersomewhat larger than the diameter of a lens to be dyed. The paper 1formed with the print area 2 is used as a print base body 10.

(3) Dyeing of a Plastic Lens

Next, explanation is made on a method of dyeing a plastic lens 3 bylocating the print base body 10 and the lens 3 in a vacuum vapordeposition transfer device 20. FIG. 2 is a schematic structural view(cross sectional view) of a dyeing jig 30.

As the material for the plastic lens 3 to be dyed, usual materials usedfor spectacle lenses are used including, for example, a polycarbonateresin (e.g., diethylene glycol bisallyl carbonate polymer (CR-39)), apolyurethane resin, an allyl resin (e.g., allyl diglycol carbonate andits copolymer, and diallyl phthalate and its copolymer), a fumaric acidresin (e.g., benzyl fumarate copolymer), a styrene resin, a polymethylacrylate resin, a fiber resin (e.g., cellulose propionate), etc.

The transfer device 20 is provided, at the front, with a take-out portnot shown for taking in and out the lens 3 and the print base body 10.Numeral 21 is a halogen lamp for heating to sublimate a dye in the printarea 2. Numeral 22 is a rotary pump which is used to produce almost avacuum in the transfer device 20. Numeral 23 is a leak valve which isopened to introduce outside air into the substantially evacuatedtransfer device 20 to recover the atmospheric pressure.

Numeral 30 denotes a dyeing jig for placing the lens 3 and the printbase body 10 in the transfer device 20. The jig 30 includes a lensplacing part 31 for placing the lens 3 and a base body placing part 32for placing the print base body 10.

The lens placing part 31 includes a cylindrical support 31 a forsupporting the lens 3 at a predetermined height and a cylindrical holder31 b for holding the lens 3. The lens 3 can be placed at a predeterminedheight when the holder 31 b holding the lens 3 on a convex surface sidethereof is put on the support 31 a as shown in FIG. 2.

A base body placing part 32 includes a cylindrical support 32 a forsupporting the print base body 10 and a cylindrical retainer 32 b forretaining the print base body 10 from above. As shown in FIG. 2, thesupport 32 a is located such that the lens placing part 31 is positionedinside the support 32 a. The print base body 10 put on the support 32 ais securely fixed and held between the retainer 32 b and the support 32a. In this state, the print area 2 of the print base body 10 faces tothe lens 3 side (a lower side) in noncontact with the lens 3.

Using the transfer device 20 having the structure described above, thelens 3 is dyed by the following operations.

After setting the lens 3 and the print base body 10 in the jig 30, thetransfer device 20 is sealed and the pump 22 is operated to producealmost a vacuum in the device 20. The vacuum in this case is such astate depressurized to about 0.1 kPa to 5 kPa. It may be below 0.1 kPa,but it will require a high-powered exhauster. On the other hand, thehigher the pressure in the device 20, the higher the temperature neededfor sublimation of the dye. Therefore, the upper limit of the pressureis preferably set at 5 kPa and, more preferably, from 0.1 kPa to 3 kPa.

When a predetermined vacuum degree is reached in the transfer device 20,the lamp 21 is turned on to heat the print base body 10 from above. Itis preferable to set the heating temperature on the print base body 10at a temperature as high as possible within a range not causingdenaturation of the dye or deformation of the lens 3.

The heating temperature is made as high as possible in sublimation,because the heating time for color development to a desired hue anddensity can be shortened to improve the productivity.

When the print base body 10 is heated by turn-on of the lamp. 21, thedye is sublimated and evaporated from the print area 2 and deposited onthe lens 3 on the concave surface side. The print base body 10 is heatedtill almost of the dye of the print base body 2 is sublimated andevaporated.

When the heating is completed, the lamp 21 is turned off and the valve22 is opened to recover the normal pressure in the transfer device 20,and the lens 3 is taken out. Although the dye has been vapor-depositedon the lens 3, it is liable to come off in this state. Thus, the lens 3is put in an oven 60 and heated to fix the dye under normal pressures.

The step (coloring step) is executed in the sequence of heating theinside of the oven 60, and then taking out the lens 3 from the oven 60after a lapse of a predetermined time for obtaining a desired hue anddensity. The heating temperature in the oven 60 is desirably as high aspossible within a range not causing denaturation of the dye anddeformation of the lens 3. For example, the heating temperature is from50° C. to 150° C. and the heating time is from 30 min. to 1 hour.

In the present embodiment, a disperse dye having a hydrophobic propertyand also a sublimating property is used for the dyeing ink, and ahumectant and a controlling agent for preventing clogging of the inkcaused by drying or the like in the cartridge of the ink jet printer orcontrolling the viscosity, the surface tension, etc. of the ink can alsobe added to the ink.

As the humectant to be used, humectants of polyhydric alcohols are usedpreferably. Specifically, they can include, for example, ethyleneglycol, diethylene glycol, polyethylene glycol, propylene glycol,dipropylene glycol, polypropylene glycol or glycerine. Further, as otherhumectants, pyrrolidones such as N-methyl-2-pyrrolidone or2-pyrrolidone, or dimethylsulfoxide or amides such as imidazolidinonemay also be used. The humectants described above are liquid moisturizingagents (humectants) and alternatively solid moisturizing agents(humectants), for example, trimethylol methane and pentose may also beused.

In a case of dyeing the lens 3 by adding the humectant for preventingdrying of the ink, while clogging due to the drying of the ink can beprevented, the humectant is sublimated and evaporated, and depositedonto the lens 3 together with the dye. When the lens 3 with thehumectant is heated (in a color developing step), cohesion of thesublimated dye or the like is caused under the effect of the humectantto bring about unevenness in the dyeing.

Accordingly, in a case of adding the humectant to the ink, a hydrophilicpolymeric material is added to the ink for preventing deposition of thehumectant on the lens 3 during sublimation of the dye. A hydrophilicpolymeric material may previously be applied on the printing surface ofthe paper 1. The hydrophilic polymeric material to be used is preferablythose preventing the sublimation of the humectant and not deterioratingthe dispersion stability of the dye, and not deteriorating thedispersion stability of the polymer of a molecular weight of 1,000 ormore and 1,000,000 or less, and those polymers of a molecular weight of1,000 or more and 1,000,000 or less are used preferably.

If the molecular weight is below 1,000, the effect of suppressing thesublimation of the humectant is less provided. On the other hand, if themolecular weight exceeds 1,000,000, the dispersion stability isdeteriorated and the ink is less discharged stably from the inkcartridge. The hydrophilic polymeric material used can include naturalpolymers, semi-synthesis polymers or entirely synthesized polymers.

The natural polymers can include, for example, plant-derived polymerssuch as gum arabic, tragacanth gum, and guar gum, see weed type polymerssuch as alginic acid or carrageenan, animal-derived polymers such asgelatin, casein and albumin, or bacteria type polymers such as xanthengum or dextrane. Further, the semi-synthesis polymers can include, forexample, cellulosic polymers such as methyl cellulose, ethyl cellulose,hdyroxyethyl cellulose, and carboxyethyl cellulose, starch seriespolymers such as sodium starch glycolate, sodium starch phosphate ester,or see weed type polymers such as sodium alginate and propylene glycolester alginate esters. Further, the entirely synthesized polymers caninclude, for example, vinylic polymers such as polyvinyl alcohol,polyvinyl pyrrolidone and polyvinyl ethyl ether, or acrylic resins suchas non-crosslinked polyacrylamide, polyacrylic acids and alkali metalsalts thereof, water soluble styrene and acrylic resins.

Further, the viscosity at a room temperature (25° C.) is preferably 1.1cps to 3.0 cps, and more preferably, 1.1 cps to 2.0 cps. Further, thesurface tension is, preferably, 20×10⁻³ N/m to 60×10⁻³ N/m and, furtherpreferably, 30×10⁻³ N/m to 50×10⁻³ N/m.

Concrete examples are shown below.

In Examples 1 to 10 and Comparative Examples 1 to 8, lens dyeing wasconducted by the vapor transfer dyeing method using various dyes and theresults of dyeing were evaluated.

EXAMPLE 1

In Example 1, a plastic lens of S-2.00 (refractive index 1.74) was used.For the dye, Dianix Yellow F-3GE (Yellow 64) made by DyStar Japan Co.,Ltd. was used. Further, Demol MS made by Kao Corporation was used forthe dispersing agent. The composition ratio for dye, dispersion agentand pure water was set to 5.0% by weight of dye, 2.5% by weight ofdispersant and 92.5% by weight of pure water.

After putting the dye, the dispersion agent and pure water at thecomposition ratio described above into the vessel, this mixture wasagitated for 10 min. or more. Subsequently, the mixture was treated by abeads mill for a specified time (30 min. treatment for about 100 g) tofinely granulate the particles of the dye into primary grains. Then, theliquid (solution) was filtrated under suction by a filter of about 1 μmpore size (glass fiber filter paper GF/B) to remove particles of largerparticle diameter and dusts. Subsequently, an appropriate amount of purewater was added and the density was adjusted to prepare an ink. When theaverage particle diameter of the dye was measured by the particlediameter distribution measuring apparatus (SALD-2000, ShimadzuCorporation), the average particle diameter was 0.3 μm.

The prepared ink (YELLOW) was injected into an ink jet printer(RJ-1300V2, Mutoh Industries Ltd.) and commercial paper (gloss paper(black) made by Mitsubishi Paper Mills Limited) was used to produce aprint base body. The print base body was produced such that a circularprint area of Φ95 in diameter was formed on a paper (base body) by usinga software (Microsoft Word) in the PC and a printing control software.Further, printing was conducted while controlling the ink dischargeamount to 50%. The ink was discharged with no clogging from the printer40.

The print base body was dried and the transfer dyeing operation from theprint base body to the lens was conducted by using the transfer device,the jig, and the like. The vacuum degree in the transfer device was 1kPa and the temperature on the print base body was 250° C. in this case.After the transfer dyeing operation to the lens, the lens was put in theoven for fixing the dye and heated at 140° C. for 2 hours to completethe color developing operation.

The dyed lens after the completion of the color developing operation wasevaluated for the hue, the color developing property, the sublimationproperty and the presence or absence of unevenness.

Hue evaluation: The hue was evaluated as “◯” in a case where thechromaticness (chroma saturation) was high and colored in a single colorand as “X” in a case where the hue was a mixed color.

Color development evaluation: After color development, the lens waswiped with an acetone-immersed cloth and evaluated as “◯” in a casewhere the dye was not peeled, as “Δ” in a case where it was slightlypeeled, and as “X” in a case where it was peeled greatly.

Sublimation evaluation: It was evaluated as “◯” in a case where the dyedid not remain on the base body after transfer, as “Δ” in a case whereit remained slightly, and as “X” in a case where it remained to such anextent as showing no substantial difference with that upon printing.

Presence or absence of unevenness: It was evaluated as “◯” in a casewhere the lens was uniformly dyed and as “X” in a case where it was dyedunevenly.

Table 1 shows the results of the evaluations as described above.

EXAMPLE 2

A plastic lens was dyed by using the same composition, ratio and thedyeing method as those in Example 1 except for using the dye of PalanilYellow FD-3GE (Yellow 54) made by Mitsui BASF Dye Co. The dyed lensafter completion of the color developing operation was evaluated for thehue, the color developing property, the sublimation property andpresence or absence of unevenness. Table 1 shows the results of theevaluations.

EXAMPLE 3

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye ofSumikaron UL Yellow 4GF (Yellow 51) made by Sumitomo Chemical Co., Ltd.The dyed lens after completion of the color developing operation wasevaluated for the hue, the color developing property, the sublimationproperty and presence or absence of unevenness. Table 1 shows theresults of the evaluations.

EXAMPLE 4

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye of KayaronAQ-LE (Kayaron Microester AQ-LE) made by Nippon Kayaku Co., Ltd. Thedyed lens after completion of the color developing operation wasevaluated for the hue, the color developing property, the sublimationproperty and presence or absence of unevenness. Table 1 shows theresults of the evaluations.

EXAMPLE 5

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye of TerasilPink 3G (Red 302) made by Ciba Specialty Chemicals K.K. The dyed lensafter completion of the color developing operation was evaluated for thehue, the color developing property, the sublimation property andpresence or absence of unevenness. Table 1 shows the results of theevaluations.

EXAMPLE 6

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye of PalanilRed C-BEL (Red 92) made by Mitsui BASF Dye Co. The dyed lens aftercompletion of the color developing operation was evaluated for the hue,the color developing property, the sublimation property and presence orabsence of unevenness. Table 1 shows the results of the evaluations.

EXAMPLE 7

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye ofSumikaron Red E-FBL (Red 60) made by Sumitomo Chemical Co., Ltd. Thedyed lens after completion of the color developing operation wasevaluated for the hue, the color developing property, the sublimationproperty and presence or absence of unevenness. Table 1 shows theresults of the evaluations.

EXAMPLE 8

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye of KayaronLight Red B-S (BS-200 (Red 152)) made by Nippon Kayaku Co., Ltd. Thedyed lens after completion of the color developing operation wasevaluated for the hue, the color developing property, the sublimationproperty and presence or absence of unevenness. Table 1 shows theresults of the evaluations.

EXAMPLE 9

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye ofSumikaron Blue E-FBL (Blue 56) made by Sumitomo Chemical Co., Ltd. Thedyed lens after completion of the color developing operation wasevaluated for the hue, the color developing property, the sublimationproperty and presence or absence of unevenness. Table 1 shows theresults of the evaluations.

EXAMPLE 10

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye ofSumikaron Blue S-BG (Blue 73) made by Sumitomo Chemical Co., Ltd. Thedyed lens after completion of the color developing operation wasevaluated for the hue, the color developing property, the sublimationproperty and presence or absence of unevenness. Table 1 shows theresults of the evaluations.

EXAMPLE 11

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye of DianixBlue AC-E (a main component; anthraquinone dye) made by DyStar JapanCo., Ltd. The dyed lens after completion of the color developingoperation was evaluated for the hue, the color developing property, thesublimation property and presence or absence of unevenness. Table 1shows the results of the evaluations.

COMPARATIVE EXAMPLE 1

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye of DianixBrilliant Yellow 5G-E (Yellow 71) made by DyStar Japan Co., Ltd. Thedyed lens after completion of the color developing operation wasevaluated for the hue, the color developing property, the sublimationproperty and presence or absence of unevenness. Table 1 shows theresults of the evaluations.

COMPARATIVE EXAMPLE 2

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye of DianixYellow AM-42 (Yellow 42) made by DyStar Japan Co., Ltd. The dyed lensafter completion of the color developing operation was evaluated for thehue, the color developing property, the sublimation property andpresence or absence of unevenness. Table 1 shows the results of theevaluations.

COMPARATIVE EXAMPLE 3

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye of TerasilYellow 4G (Yellow 211) made by Ciba Specialty Chemicals K.K. The dyedlens after completion of the color developing operation was evaluatedfor the hue, the color developing property, the sublimation property andpresence or absence of unevenness. Table 1 shows the results of theevaluations.

COMPARATIVE EXAMPLE 4

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye ofSumikaron Rubine SE-GL (Red 73) made by Sumitomo Chemical Co., Ltd. Thedyed lens after completion of the color developing operation wasevaluated for the hue, the color developing property, the sublimationproperty and presence or absence of unevenness. Table 1 shows theresults of the evaluations.

COMPARATIVE EXAMPLE 5

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye of DianixRed KB-SE made by DyStar Japan Co., Ltd. The dyed lens after completionof the color developing operation was evaluated for the hue, the colordeveloping property, the sublimation property and presence or absence ofunevenness. Table 1 shows the results of the evaluations.

COMPARATIVE EXAMPLE 6

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye of DianixRed S-4G made by DyStar Japan Co., Ltd. The dyed lens after completionof the color developing operation was evaluated for the hue, the colordeveloping property, the sublimation property and presence or absence ofunevenness. Table 1 shows the results of the evaluations.

COMPARATIVE EXAMPLE 7

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye of KayalonPolyester Red TL-SF (Red 323) made by Nippon Kayaku Co., Ltd. The dyedlens after completion of the color developing operation was evaluatedfor the hue, the color developing property, the sublimation property andpresence or absence of unevenness. Table 1 shows the results of theevaluations.

COMPARATIVE EXAMPLE 8

A plastic lens was dyed by using the same composition ratio and thedyeing method as those in Example 1 except for using the dye of DianixNavy Blue BG-SE200 made by DyStar Japan. Co., Ltd. The dyed lens aftercompletion of the color developing operation was evaluated for the hue,the color developing property, the sublimation property and presence orabsence of unevenness. Table 1 shows the results of the evaluations.

TABLE 1 Color Un- Sub- Comprehensive Color Manufacturer Product Name C.INo. Remarks Hue development evenness limation evaluation Yel- Ex. 1Dystar Japan Dianix Yellow Yellow64 quinophthalone dye ∘ ∘ ∘ ∘ low F-3GEEx. 2 Mitsui BASF Palanil Yellow Yellow54 quinophthalone dye ∘ ∘ ∘ ∘ DyeFD-3GE Ex. 3 Sumitomo Sumikaron UL Yellow51 anthraquinone dye ∘ 0 ∘ ∘Chemical Yellow 4GF Ex. 4 Nippon Kayaron — quinophthalone dye ∘ 0 ∘ ∘Kayaku AQ-LE C. Ex. 1 Dystar Japan Dianix Brilliant Yellow71naphthalimido dye x ∘ ∘ x Yellow 5G-E C. Ex. 2 Dystar Japan DianixYellow Yellow42 nitro dye ∘ x ∘ x AM-42 C. Ex. 3 Chiba Specialty TerasilYellow211 azo dye red- ∘ ∘ ∘ x Chemicals Yellow 4G tinted Red Ex. 5Chiba Specialty Terasil Red302 anthraquinone dye ∘ ∘ ∘ ∘ Chemicals Pink3G Ex. 6 Mitsui BASF Palanil Red Red92 anthraquinone dye ∘ ∘ ∘ ∘ DyeC-BEL Ex. 7 Sumitomo Sumikaron Red60 anthraquinone dye ∘ ∘ ∘ ∘ ChemicalRed E-FBL Ex. 8 Nippon Kayaron Light Red152 azo dye of ∘ ∘ ∘ ∘ KayakuRed B-S thiazole type (BS-200) C. Ex. 4 Sumitomo Red Sumikaron Red73 azodye Δ ∘ ∘ x Chemical Rubine SE-GL C. Ex. 5 Dystar Japan Dianix — azo dyex ∘ Δ x Red KB-SE C. Ex. 6 Dystar Japan Dianix — azo dye Δ x ∘ x RedS-4G C. Ex. 7 Nippon Kayalon Polyester Red323 azobenzen dye x ∘ Δ xKayaku Red TL-SF Blue Ex. 9 Sumitomo Sumikaron Blue56 anthraquinone dye∘ ∘ ∘ ∘ Chemical Blue E-FBL Ex. 10 Sumitomo Sumikaron Blue73anthraquinone dye ∘ ∘ ∘ ∘ Chemical Blue S-BG Ex. 11 Dystar Japan DianixBlue — anthraquinone dye ∘ ∘ ∘ ∘ AC-E C. Ex. 8 Dystar Japan Dianix Navy— azo dye reddish ∘ x Δ x Blue BG-SE200 black (C.Ex.: ComparativeExample)

<Results>

As shown in Table 1, for the yellow (YELLOW) dyes, good result wasobtained by the quinophthalone dye and the anthraquinone dye. The dyeused in Comparative Example 3 was favorable in view of the colordeveloping, unevenness, sublimation property but since it resulted inred-tinted hue, it was not suitable to yellow dyeing. Further, for thered (RED) dyes, good result was obtained by the anthraquinone dye andthe thiazole type dye and, for the blue (BLUE) dye, good result wasobtained by the anthraquinone dye.

Further, the lens of Example 1 (S-2.00, refractive index 1.74) was dyedby the dyeing method using the dyes used in Examples 1 to 9 andComparative Examples 1 to 8, but the lens was dyed only slightly andcould not be dyed in a desired density.

Then, the dyeing density for the lens in a case of variously changingthe density of the dye in the ink was evaluated.

<Condition A>

As the dye to be used, Kayaron AQ-LE (YELLOW dye in Example 4), KayaronLight Red B-S (RED dye in Example 8) and Sumikaron blue E-FBL (BLUE dyein Example 9) were used. Kao Demol MS was used for the dispersant.

The ink prescription (composition ratio) for the condition A was: 1.0%by weight of dye, 0.5% by weight of dispersant and 98.5% by weight ofpure water. The ink was prepared by the same procedures as those inExample 1.

A print base body was prepared by an ink jet printer (Super-mechie, madeby Intack Corporation). Further, the discharge amount from each of theink discharge heads for printing on the paper (base body) was at 100%for each color in case of outputting in a single color and at 50% foreach color in case of outputting in a mixed color.

The transfer dyeing operations were performed using CR-39 for theplastic lens under the color developing condition of 135° C., for 1hour, and in the same manner as in Example 1. The chromaticity of thedyed plastic lens (after color development) was measured by using acolor measuring device (DOT-3, manufactured by Murakami Color ResearchLaboratory). Table 2 shows the results thereof.

<Condition B>

The condition was identical with the condition A except for changing thecomposition ratio of the ink to 2.0% by weight of dye, 1.0% by weight ofdispersant and 97.0% by weight of pure water. The chromaticity of thedyed plastic lens (after color development) obtained in the same manneras the condition A was measured by using the color measuring device.Table 2 shows the results thereof.

<Condition C>

The condition was identical with the condition A except for changing thecomposition ratio of the ink to 5.0% by weight of dye, 2.5% by weight ofdispersant and 92.5% by weight of pure water. The chromaticity of thedyed plastic lens (after color development) obtained in the same manneras the condition A was measured by using the color measuring device.Table 2 shows the results thereof.

<Condition D>

The condition was identical with the condition A except for changing thecomposition ratio of the ink to 10.0% by weight of dye, 5.0% by weightof dispersant and 85.0% by weight of pure water. The chromaticity of thedyed plastic lens (after color development) obtained in the same manneras the condition A was measured by using the color measuring device.Table 2 shows the results thereof.

<Condition E>

The condition was identical with the condition A except for changing thecomposition ratio of the ink to 20.0% by weight of dye, 10.0% by weightof dispersant and 70.0% by weight of pure water. The chromaticity of thedyed plastic lens (after color development) obtained in the same manneras the condition A was measured by using the color measuring device.Table 2 shows the results thereof.

<Condition F>

The condition was identical with the condition A except for changing thecomposition ratio of the ink to 30.0% by weight of dye, 15.0% by weightof dispersant and 55.0% by weight of pure water. The viscosity was highand therefore stable printing could not be performed. In addition,cohesion of the dye was also observed.

TABLE 2 Condition Condition Condition Condition Condition Condition A BC D E F Composition ratio Dye 1.00% 2.00% 5.00% 10.00% 20.00% 30.00%Dispersant 0.50% 1.00% 2.50% 5.00% 10.00% 15.00% Pure water 98.50%97.00% 92.50% 85.00% 70.00% 55.00% Chromaticity (Red) Y 70.05 54.6 35.4525.28 17.15 L* 87.02 78.81 66.08 57.35 48.45 a* 17.92 38.43 62.64 75.0478.65 b* −2.94 −6.76 −6.15 1.06 7.96 Chromaticity (Yellow) Y 92.51 91.9890.97 89.81 82.53 L* 97.03 96.81 96.4 95.92 92.81 a* −1.86 −4.58 −9.41−14.01 −16.73 b* 8.56 11.69 25.64 42.35 58.42 Chromaticity (Blue) Y84.25 80.25 66.77 47.4 29.47 L* 93.56 91.8 85.39 74.45 61.19 a* −1.40−3.77 −7.73 −12.34 −12.03 b* −4.32 −7.1 −16.31 −31.99 −45.3 Chromaticity(Mixed color) Y 76.77 56.56 39.74 19.13 11.04 L* 90.22 79.93 69.28 50.8439.65 a* 8.38 15.82 28.33 43.5 46.65 b* −0.68 −1.25 −2.61 0.04 2.67Dyeing density about 30% about 50% about 65% about 75% about 85%

<Results>

Under the condition A (dye concentration: 1.0%), the lens could be dyedat about 20% of the dyeing density in the mixed color (50% output foreach color). In this case, the ink prescription under the condition Acan be applied only to about 10% of all the products correspondinglydyed by the dip dyeing method.

Under the condition B (dye concentration: 2.0%), the lens could be dyedat about 40% of the dyeing density in the mixed color. In this case, theink prescription under the condition B can be applied to about 30% ofall the products correspondingly dyed by the dip dyeing method.

Under the condition C (dye concentration: 5.0%), the lens could be dyedat about 60% of the dyeing density in the mixed color. In this case, theink prescription under the condition C can be applied to about 70% ofall the products correspondingly dyed by the dip dyeing method.

Under the condition D (dye concentration: 10.0%), the lens could be dyedat about 75% of the dyeing density in the mixed color. In this case, theink prescription under the condition D can be applied to about 90% ofall the products correspondingly dyed by the dip dyeing method.

Under the condition E (dye concentration: 20.0%), the lens could be dyedat about 85% of the dyeing density in the mixed color. In this case, theink prescription under the condition E can be applied to almost all theproducts which is correspondingly dyed by the dip dyeing method.

Under the conditions B or C, the dyeing density can be brought to 60% to70% by repeating the transfer dyeing operations twice or three times.However, when the dye concentration is lowered as far as 1.0% (conditionA), the dyeing density does not sometimes reach 70% unless the transferdyeing operation is repeated by 5 to 10 times. Such a method is actuallypoor in view of the operation performance and is not practical.

Then, in a case of adding the humectant to the ink, the effect thereofon the lens dyeing was evaluated.

EXAMPLE 12

In Example 12, a CR-39 lens was used. The used dyes were Kayaron AQ-LE(YELLOW), Kayaron Light RED B-S (RED), Dianix BLUE AC-E (BLUE).Furthermore, the used dispersant was Demol-MS made by Kao.

Table 3 shows the composition for each ink put in each cartridge.

TABLE 3 RED YELLOW BLUE Dye 1.0% 3.0% 3.0% Dispersant 0.5% 0.5% 0.5%Pure water 98.5%  96.5%  96.5%  In this table, “%” means “% by weight”.

After putting the dye, the dispersant and pure water in each compositionas shown in Table 3 into each vessel, these mixtures were agitated for10 min. or more. Subsequently, they were treated by an ultrasonichomogenizer for a specified time (30 min. treatment for about 100 g) tofinely granulate the particles of the dye into primary particles. Then,each liquid (solution) was filtrated under suction by a filter of about1 μm pore size (glass fiber filter paper GF/B) to remove particles oflarger particle size and dusts. An appropriate amount of pure water wasfurther added for regulation of the density to prepare inks. When theaverage particle diameter of the dye was measured by the particlediameter distribution measuring apparatus (SALD-2000, manufactured byShimadzu Corporation), the average particle diameter was 0.3 μm.

Each of the prepared inks was injected into an ink jet printer(RJ-1300V2, manufactured by Mutoh Industries Ltd.) and commercial paper(gloss paper (black) made by Mitsubishi Paper Mills Limited) was used toproduce a print base body. The print base body was produced such that acircular print area of Φ95 in diameter was formed on the paper (basebody) by using the PC's software (Microsoft Word) and a printing controlsoft. Further, the hue was set to R150, G100 and B50.

The print base body was dried, and the transfer dyeing operation fromthe print base body to the lens was conducted by using the transferdevice, the jig, and the like described above. The vacuum degree in thetransfer device was 1 kPa and the temperature on the print base body was250° C. in this case. It was confirmed that almost of the dye sublimatedfrom the print area of the print base body and deposited on the lens.After the transfer dyeing operation to the lens, the lens was placed inthe oven for fixing the dye and heated at 135° C. for 1 hour to completethe color developing operation.

EXAMPLE 13

In Example 13, inks added with the humectant and the polymeric materialwere used. The material of the lens, the dye and the dispersantidentical with those of Example 12 were used. Glycerin was used for thehumectant and methyl cellulose 25 was used for the hydrophilic polymericmaterial.

Table 4 shows the composition for each ink filled into each inkcartridge.

TABLE 4 RED YELLOW BLUE Dye 1.0% 3.0% 3.0% Dispersant 0.5% 0.5% 0.5%Pure water 78.3%  76.3%  76.3%  Glycerine 20.0%  20.0%  20.0%  Methylcellulose 0.2% 0.2% 0.2% In this table, “%” means “% by weight”.

After putting the dye, dispersant, pure water, humectant and polymericmaterial of the compositions as shown in Table 4 into each vessel, eachmixture was agitated for 10 min. or more. Then, each mixture was treatedfor a specified time by the ultrasonic homogenizer (30 min. treatmentfor about 100 g), filtered under suction through a filter, and purewater was further added by an appropriate amount to regulate theconcentration to prepare inks. The average particle diameter was 0.3 μm.

Each prepared ink was injected into each ink cartridge of an ink jetprinter (MJ-520C manufactured by EPSON) and the print base body wasproduced by the same procedures as in Example 12 and the transfer dyeingoperation to the lens was conducted.

Since the ink discharge port (head portion) of the ink cartridge wassmaller in the printer used in Example 13 compared with the printer usedin Example 12, it was worried about the clogging due to the drying ofthe ink. However, by addition of the humectant to the ink, printing onthe paper could be conducted, thus producing the print base body with noclogging due to drying even in a case of using the printer repetitively.After drying the print base body, the transfer dyeing operation and thecolor developing operation were conducted under the same conditions asthose in Example 12.

When the lenses after color development were observed, it was found thatthe lenses were dyed uniformly with no unevenness in a brownish color at32.0% of a luminous transmittance (measured at 100 visual field by useof a D65 light source of a color measuring device DOT-3, manufactured byMurakami Color Research Laboratory).

EXAMPLE 14

In Example 14, inks prepared by adding a humectant (glycerine) to eachink in Example 12 were used.

Table 5 shows an ink prescription.

TABLE 5 RED YELLOW BLUE Dye 1.0% 3.0% 3.0% Dispersant 0.5% 0.5% 0.5%Pure water 78.5%  76.5%  76.5%  Glycerine 20.0%  20.0%  20.0% 

The inks were prepared in the same manner as in Example 12 to completethe inks. Further, a polymeric material was coated to the paper used forthe print base body (gloss paper (black) made by Mitsubishi Paper MillsLimited) on the side of a surface to be printed. Methyl cellulose 400was used for the polymeric material, which was dissolved into water as a10% solution and then coated with no unevenness on the side of theprinting surface by a brush, followed by drying.

After setting the paper coated with methyl cellulose in an ink jetprinter (MJ-520C, manufactured by EPSON), a print base body was producedby the same procedures as those in Example 12. Printing was conductedwith no clogging from the printer to the paper, and the print base bodycould be produced. After drying the print base body, the transfer dyeingoperation and the color developing operation were conducted under thesame conditions as those in Example 12.

When the lenses after color development were observed, it was found thatthe lenses were dyed uniformly with no unevenness in a brownish color at29.5% of luminous transmittance.

COMPARATIVE EXAMPLE 9

In Comparative Example 9, the polymeric material was not used and aprint base body was produced by using the ink in Example 14 (inkprescription in Table 5). The transfer dyeing operation and the colordeveloping operation were conducted with other conditions beingidentical with those in Example 12. When the lenses after colordevelopment were observed, it was found that the lenses were dyedunevenly.

INDUSTRIAL APPLICABILITY

As described above, according to the present invention, the plastic lenscan be dyed favorably by the vapor deposition transfer dyeing method.

1. A method of dyeing a plastic lens, comprising: applying, selectivelyor in combination, a first ink comprising a sublimatable disperse yellowdye, a second ink comprising a sublimatable disperse red dye, and athird ink comprising a sublimatable disperse blue dye, to a base bodyusing an ink jet printer to form a print area on the base body; placingthe base body and the lens so that the print area faces, but does notcontact, a surface of the lens to be dyed; and heating at least theprint area of the base body under a vacuum to sublimate and deposit thedye on the surface of the lens; wherein: the yellow dye is ananthraquinone dye, or a quinophthalone dye; the red dye is ananthraquinone dye or an azo dye of thiazole type; the blue dye is ananthraquinone dye; and each of the first, second and third inks furthercomprises a dispersant for dispersing the respective dye in an aqueoussystem, a humectant for preventing drying of the respective ink, and ahydrophilic polymeric material for preventing sublimation of therespective humectant during sublimation of the respective dye; and therespective polymeric materials are selected so as not to deteriorate adispersion stability of the dye.
 2. The method to claim 1, furthercomprising heating the lens to a predetermined temperature after the dyehas been deposited on the lens.
 3. A method of dyeing a plastic lens,comprising: forming a print area on a base body by coating the base bodywith a hydrophilic polymeric material; applying, selectively or incombination, a first ink comprising a sublimatable disperse yellow dye,a second ink comprising a sublimatable disperse red dye, and a third inkcomprising a sublimatable disperse blue dye, to the formed print area ofthe base body using an ink jet printer; placing the base body and thelens so that the print area and a surface of the lens to be dyed face,but do not contact, each other; and heating at least the print areaunder a vacuum to sublimate and deposit the dye on the surface of thelens; wherein: the yellow dye is an anthraquinone dye or aquinophthalone dye; the red dye is an anthraquinone dye or an azo dye ofthiazole type; the blue dye is an anthraquinone dye; and each of thefirst, second and third inks further comprises a dispersant fordispersing the respective dye in an aqueous system and a humectant forpreventing drying of the respective ink.